Question

At constant pressure, which of these systems do work on the surroundings? Check all that apply.

2A (g) + B(s) --> 3C(g)
2A (g) +2B (g) -->5C(g)
A(g)+ B(g) --> C(g)
A (s) +2B(g)--> C(g)

Answer 1

I think the answer(s) is/are A and B.

A increases (note B is a solid) from 2 moles to 3 moles so that is an expansion. B is an expansion from 4 moles (2+2) to 5 moles C.
PLEASE confirm when you enter into the database. I like to make sure I'm right. ;-).

Answer 2

You can select more than one answer and I can't seem to figure it out.

Answer 3

Yes! It is right. Thank you for your help. I really appreciate it.

Answer 4

If -p(V2-V1) and the system is to do work on the surroundings, doesn't that mean that the gas must expand? So which systems expand?

Answer 5

I think it is only the first one, but it marked me wrong.

Answer 6

sorry i meant the second one. I put the second one and it marked me wrong. As well, I put the last two and it marked me wrong also.

Answer 7

Thank you.